Maneuverable target simulating apparatus for ordnance training



March 21, 1950 E. ODIN 2,501,350

MANEUVERABLE TARGET SIMULATING APPARATUS FOR ORDNANCE TRAINING FiledJune 5, 1946 5 Sheets-Sheet l Eugene Odin V Target N GLE 1Q Z! A fl07P/VEZS March 21, 1950 E. ODIN 2,501,350

' MANEUVERABLE TARGET SIMULATING APPARATUS FOR ORDNANCE TRAINING FiledJune 5, 1946 5 SheetsSheet 2 Fig. 2

ATUS

March 21, 1950 E. ODIN MANEUVERABLE TARGET SIMULATING APPAR FOR ORDNANCETIRAINING 5 Sheets-Sheet 5 Filed June 5, 1946 INVENTOR. Eugene Odin BY WX44 March 21, 1950 E. ODIN MANEUVERABLE TARGET SIMULATING APPARATUS FORORDNANCE TRAINING 5 Sheets-Sheet 4 Filed June 5, 1946 II .m d m a I .M ef QU I E n I I I 4 ,0 W e I I 5 l W:

V I I I III E m I I 5 I I 5 I I I I I 0 m ..V I I I I I \I I I. I

I I \i l II I I I II I I I I I lllll ll vI I F March 21, 1950 E. ODINMANEUVERABLE TARGET SIMULATING APPARATUS FOR ORDNANCE TRAINING 5SheetsSheet 5 Filed June 5, 1946 .Hwil

INVENTOR. Eugene Odin Patented Mar. 21, 1950 MANEUVERABLE TARGETSIMULATING AP PARATUS FOR ORDNANCE TRAINING 1 Eugene Odin, Brooklyn, N.Y., assignor to Anna Corporation, Brooklyn, N. Y., a corporation of NewYork Application June 5, 1946, Serial No. 674,504

14 Claims.

This invention relates to ordnance apparatus;

and has particular reference to apparatus for instruction in the use ofthe complicated instruments for directing projectiles to targets,especially submarine torpedoes, although the invention is not limited tothat use.

In training candidates for fire or torpedo control officers, includingsubmarine command, it is impractical to shoot projectiles, such astorpedoes,

at real ships for training purposes, so that it,

has become the practice to provide model ships variously arranged formovement relatively to the observation station, and imaginaryprojectiles are aimed and fired at such models in simulation of actualbattle action. Such arrangements,

while useful in elementar training and familiarization with theobservation and calculating instruments, provide but meager instructionin actual battle conditions, and hence-a more realistic arrangement forthat purpose is desirable.

In accordance with the present invention, training apparatus isprovided, in which a number of ship models are movably arranged on amount in simulation of a ship convoy target with mechanism under thecontrol of the instructor for moving themodel mount bodily, for rotatingthe same and for adjusting the rotation of one .or more of the modelsrelatively to the others.

The usual means is provided for determining the percentage of hits madeby imaginary projectiles, such as torpedoes, aimed and fired at selectedunits of the convoy target according to standard calculated dataprovided by actual computing instruments.

The training apparatus of this invention is particularly characterizedby the arrangement of.

the model mount which comprises a rotor mounting an inverted group ofship models simulating the ships of a convoy, a central rotatableportion thereof having gearing for driving the same, and

outstanding extensions on the central portion vided for oscillating thecentral portion of the main rotor at will, so as. to simulate evasivezigzag motion of the target, and the curtains simulating the surface ofthe sea depend from the main rotor behind and adjacent the models, andbeing flexible, move as the Iarge rotor moves, so that realisticsimulation of the moving surface of the sea is provided. The centertrunnions for the models have separate bayonet joint connections withsockets for substituting different models, the members provided withsuch sockets having the aforementioned worm gears.

It will be seen that with the ordnance model. mounting of this inventionand the cooperating elements used in conjunction with standardcalculating and aiming apparatus, personnel may be trained underconditions accurately simulating those of actual battle, and without theexpense and nuisance of conducting full scale training operations at aremote site available for them.

For a more complete understanding of the invention, reference may be hadto the accom panying drawings, in which:

Figure 1 is an expanded perspective view of the ordnance trainingapparatus of this invention, adapted to submarine torpedo aiminginstruction;

Fig. 2 is an enlarged axial section through the rotor as seen along theline 22 of Fig. 1;

Figs. 3a and 3b jointly constitute a detailed cross-sectional view asseen along the line 3-3 of Fig. 1 through the main rotor carrying theship models and showing the driving means of a ship model of the convoygroup;

Fig. 4 is a bottom view of the rotatable mounting and driving means forone of the convoying destroyers, as seen along the line 4-4 of Fig. 5;and

Fig. 5 is an enlarged transverse section through the mounting means ofFig. 4, as seen along the line 5-5 thereof.

Referring to Fig. 1, numeral 33 designates the rotor for the screenships of the rotary model system supported on square carriage II movablydepending by rollers I3 from barn-door type rails i2, only one of whichis shown, the other rail being understood to lie above the plane of thedrawing. The rollers I3 on carriage I I are double rollers and the railsI2 are re-entrant rails to receive them accurately. Firmly fixed to thecarriage II is an up-standing strut II for connecting the carriage I Ito the cable I4 passing around idler sheave I5 and driving sheave I 5',the former beingcarried on shaft l6 mounted on tightening block W,slidably mounted on a casting secured to the rails I2 to the left andhaving a screw and not combination similar to that shown at 26 to 3 bedescribed, for taking up slack in the drive cable [4. Cable i i drawsthe whole main assembly ll, 33, back and forth on the rails l2 for rangechange effect on an cbservers periscope P, shown at the right, thischange of range being provided by a known type of target data computerC, as will be described, and is utilized to control motor 85 connectedto sheave 5 for driving the same and the connected cable l4.

Two additional cables, l8 and i9 (driven at their ends, not shown) passpartly around large sheaves 2D and 2 I, respectively, carried bycarriage ll, whose motions cause rotation of sheaves 20 and 2!. The areof contact between cables 18 and I9 and large sheaves 20 and 2! isincreased by passage of these cables i 8 and I9 over pairs of idlersheaves 22, 23. Idler sheaves 22 and 24 are carried by carriage l lwhile idlers 24 are mounted on a bracket 26 attached to carriage H. Theidler sheaves 2a are provided with cable-tightening means comprising anut and Screw combination 25 interposed between the shaft of sheaves 24and bracket 28 whereby the cables 18 and 19 may be tightened againstsheaves 2B and 2i. Sheaves 23, being carried on shaft l6, are adjustedwhen sheave I is adjusted to thereby tighten cable l4 at that point.

The upper large sheave 20, by its shaft 2|, journalled in tubular shaft2 i rotating on frame II, and gearing 52, drives the lower gear 88 ofdifferential 41 whose spider drives upper large gear 39 through pinions48. Large gear 39 is pinned to shaft 38 journalled in tubular shaft 44and carries at its lower end the gear 38 meshing with a train of gears41 carried by a member 43 shown as a radial bar in Fig. 1, but actuallya disc as shown, in Fig. 2. Similarly, the lower sheave 2!, through itstubular shaft 2|" journalled in frame H, and its integral pinion 63,drives the upper gear 6| of differential 4!, which is connected by gears62 and 63 to the lower large gear 45 connected to tubular shaft 44carrying at its lower end the member 43, so that the latter rotates withshaft 44 and carries the gear train 41 With it.

particularly in Fig. 2. As there shown, a secondary disc 43 shown as aradial bar in Fig. 1 is also carried in the recess of main disc 33,although the former moves relatively to the latter. Main disc 33 isrotated on its bearings 34 and 35 by a pinion 49' meshing with a gear 54on disc 33 and connected to shaft 49, whose operation willbe described.

J ournalled on tubular shaft 44 is a sleeve pinion 65 driven by gear B4connected to the inner gear of the train 4? carried by secondary disc43, as shown in Figs. 1 and 2. Sleeve gear 65 in turn drives gears 66and 6'! through intermediate gearing 35' shown in Figs. 1 and 3a. Sincethe parts driven by gears 66 and 67 are the same, the

drive of the latter will be described in connection with Figs. 1, 3a,3b, 4 and 5.

Referring to Fig. 3a, gear 66 is shown driving a pinion 66' fixed on along non-radial shaft 68 journalled on rotary disc 33. As shown in Figs.3b, 4 and 5, the free end of shaft 68 is fitted with a worm 68' whichmeshes with a worm wheel 88", shown in Fig. 5 as carrying a socketedstub'shaft 6 9 journalled in disc 33. As shown particularly in Fig. 1,non-radial shaft 65 and its identical "appurtenant parts are also drivenfrom gear 66,

whereas gear 6''! similarly drives non-radial shafts it and H and partsidentical to those shown in Figs. 3a, 3b, 4 and 5. It will be understoodthat certain parts of Fig. 1, such as shafts 38 and 44, have been showndisproportionately long or otherwise out of proportion, in the interestof clarity, actual proportions being shown by Figs. 2, 3a, 3b, 4 and 5.

The arrangement of ship models is shown in skeleton form in Fig. 1, andincludes a model of a relatively large target ship 21 at the center ofthe convoy, which is represented by the models of outlying destroyers28, 29, 30 and 3| and the attendant cruiser 32, or other target craft inany other arrangement.

As shown particularly in Figs. 2 and 5, the ship models are mountedupside down in order to be freely accessible from the floor forinterchanging the models or substituting different models, each mountingfor these models being equipped with a bayonet joint socket such as isshown at 31 in Fig. 2, with which ship model 21 is connected to shaft38, as shown in Fig. 2. A similar bayonet joint socket is designated 31'in Fig. 5 for connecting and disconnecting models 28 from shaft 69.

The distant periscope P, with which the ship models are viewed, ispositioned in the direction of arrow 48 in Figs. 1 and 2 and is ofstandard optical construction except that it is equipped with anerecting lens so that the ship models appear right side up in its fieldof view.

Suspended from concentric rings on the under side of rotary disc 33 arecurtains 56, of sea green material, such as cloth, which being flexible,permits the assembly of ships to approach so closely the periscope Pthat it lies within the circle of destroyers for special close-uptraining. As motion is imparted to disc 33, the sea green clothconstituting curtains 56 and 56, realistically simulate the surface ofthe ocean as seen in the periscope P. The inversion of the ship modelsenables the curtains to swing and move at will by gravity and serve as amobile background for the model ships and for changing models.

Having described the structure which carries the ship models, theadditional mechanism which causes it to rotate and oscillate will bedescribed. As previously stated, the movement of the sheaves 2B and 2|is by cables 58 and 19, which are driven by motor mechanism similar to85 on Fig. 1 from computer C, and impart relatively rotation totelescoped shafts 38 and 44, which in turn move the secondary disc 43,its appurtenant gearing 41, and outlying ship models 28,29, 30 and 3!,as well as ship models 21 and 32. This movement is modified by rotationof main disc 33 by coaction between its gear 54 and meshing pinion 45)"on the lower end of shaft 49 connected to the spider of differential 48,the output of which is a compound motion of the direct rotation ofsheave 2i and a special oscillating motion superimposed by motor uponthe steady motion of sheave 20.

This oscillating motion is fed into differential 5| by gearing 52, andis imparted by motor 50 through linkage system at the will of theobserver at the periscope station P, and may be produced by a switch Sconnected to the motor 50 by cable 51, in order to make the rotor 33 forthe screen ships oscillate bath and forth to give the illusion in thefield of view of the periscope that the whole-convoy of model ships iszigzaggin g. This oscillation-producing linkage system 55 is connectedby a gear sector and pinion combina-- tion 12 to the spider of thedifferential 5|.

The compound motion output of differential is amplified by servo-system53, including the slow speed follow-up transmitter 16 and the high speedfollow-up transmitter 11, both of conventional construction, by means ofshaft 13 driven from the upper gear of differential 5| and connected totransmitters 18 and 11 through worm and worm wheel combinations I4 and15, respectively. Follow-up transmitters I6 and 11 are connected bycables 18 and 19 to follow-up motor 80 which, through gearing 8|, drivesthe lower gear 82 of differential 48, whose spider drives shaft 49, asstated. Follow-up of transmitters 1B and 11 are restored mechanically inthe usual way, by the shaft 8| and appurtenant gearing connected togearing 8|, as shown.

Further superimposed upon the motion imparted by the aforementionedmechanism to the ship models is a manual motion introduced by hand crank42 connected through differential 48 and gearing 62, 63 and 45 totubular shaft 44, so as to change the angular position of member orsecondary disc 43 and with it the ship model 32. The orientation orbearing of the other ship models is not changed by action of the handcrank and continue their original motions, as does also ship model 32while being swung around.

In operation of the ordnance training apparatus of this invention, asapplied to submarine torpedo aiming and firing training, the cable M isdriven by motor 85, controlled by the range output of a target datacomputer C of conventional design, and not forming part of the presentinvention, and cables H3 and i9 are driven likewise by motors, notshown, to give target course (C) and true target bearing (B),respectively, from the same computer C. One example of such computer isdisclosed in copending application Serial No, 253,260, filed January 28,1939, by applicant and another, whereby change of range and bearing ofthe target convoy carried by rotor 33 may be generated and fed throughmotors, like that shown at 85, with respect to the student observer atdistant periscope P, representing the observation instrument of anattacking submarine, for example.

Movement of carriage ll along rails |2 toward the periscope P in thedirection of arrow 48, unless compensated, causes sheaves 20 and 2| toroll along cables I8 and I9, respectively, and consequently to rotate inunison. Owing to the error imparted by this action, compensation is madein a well known manner, which forms no part of the present invention, bymeans of differential mechanism between motor 85 and cable l4 and theother cable drives, so that true rotations of sheaves 20 and 2| occur tocompensate for their train station for range.

The lower sheave 2| drives through gearing 60 to supply values of truetarget bearing (B) to the upper input gear 6| of differential 4|, theupper input gear 86 of differential 48, and to the upper input gear 81of differential 46. The output of differential 48 is applied throughshaft 49 and gear 49' to the large gear 54 of screen ships rotor 33,which angularly positions the rotor 33 to the value of target angle (A),modified when required by the oscillatory motion imparted by motor 50.From the fire control problem, target angle (A) =true target bearing (B)target course (CH-180, where target angle (A) is defined as the anglebetween the forward and aft axis of the target and the line of sighttothe target. The output of differential is applied through output gear62, gear 63, lower large gear 45, tubular shaft 44 to member 43, whichpositions ship model 32 to the value of true target bearing (B),modified when required by the output of handwheel 42. This gives theeffect in the distant periscope P of realistic steaming of the convoywith respect to the observer's own ship on which periscope P is assumedto be mounted. On the other hand, rotation of the upper sheave 20 drivesthrough gearing 52 to supply the value of target course (0) to the lowerinput gear 88 of differential. The output of differential 4| is appliedthrough gearing 40 and upper large gear 39 to shaft 38, which positionstarget ship 21 to the value of target angle (A) to simulate change ofcourse of the convoy. This motion is transmitted through the train ofgears 38', 41 to the attendant ship 32 and also by gear 64 tothefioating sleeve gear 65, and thence to gears 65 and 61, which,respectively, drive shafts 68, 69 and shafts in, H, and rotatecorresponding ship models 28, 3|, and 29, 30, in time with the centertarget ship 21; in the same direction and at the same rate.

The upper sheave 28 also drives the bottom gear 89 of differential 5|whose output gear 12 drives the cross shaft 13 to drive slow speed andhigh speed follow-up transmitters 16 and. 11, respectively, whichenergize follow-up or servomotor 88 to drive rotor 33 through reductiongearing 8|, lower gear 82 of differential 48, shaft 49 and gearing 49and 54.

By reason of the background of sea green curtains 56 and 58' and theerection of the ship models efiected by the inverting lens of theperiscope P, the student observer obtains a very realistic impression ofa convoy of ships moving at sea in the field of view of his periscopewith the range changing in accordance with the input from the calculatorC, so that he can make his observation under simulated battle conditionsthrough a periscope identical in all respects to that of a submarineperiscope and equipped with a firing button for launching imaginarytorpedoes when the periscope is properly oriented by him on a selectedtarget among the convoy or convoying ships. By checking the studentsoperations of the firing button, an instructor can credit him with hitsor misses, as the case may be. A rotat ing prism may also be provided inthe periscope P, in a well known manner, in order to imitate therelative motion between the convoy and the attacking submarine carryingthe periscope P, while angular change in apparent convoy heading isintroduced by cable I8.

7 It will be observed that the steady rotation of screen ships rotor 33from cable l8 through the gearing and other connections described isaccompanied by an equal turning of each ship model through theintervening gearing 38', 41, 64, 65, 68, 81 and accompanying shafting68, 69, 18 and 1|, which gives the illusion of a convoy steaming fullahead. Also, change of course is given all ships of the model convoy bymeans of gear 39 driven from sheave 2|, in turn rotated by cable l9.Furthermore, oscillatory motion is imparted to the screen ships rotor 33only, by means of switch S at the observers periscope Peontrolling motor50, which introduces the corresponding oscillatory motion through thelinkages 55 in the manner described. The zigzagging or evasive action ofthe convoy is thus realistically simulated in the field of view of theperiscope P. Target angle (A) is represented by the angle of the targetship model 21, as is indicated in Fig. 1.

As previously mentioned, the convoy models may be replaced or shifted bydisconnecting them immgthein bayonet ioinaconnecti ns :1: on: 3orzreplacing them; with, othe l models at,;Wi11.,

Althoughlapreferredembodimentotathednvens tion has been, illustratedand; described, herein, it. is. to be; understood. that the: invention;is not limited. thereby, but is susceptible; i, variations inform and,detail withiuthe scop eeof; thaape ended. claims.

1-. In: ordnance; train ng; apparatus, including an observationinstrument, thecombination, ot a: relatively remote target. model, at;least; one. Stationary rail, a canriagamounted n;saidrail. averticalshaft thereon-,a support for saidmQdel carried by said shaft, ahorizontal mechanism fog;- moving. said carriage along, said. rail,operative connections: between said shaft; andsaid support, and. means.driven independently of, saidmfiehaf nism for; rotating, said shaftandsupnort wherebs said, model is moved in thefield. of. view of; saidinstrument" 2 ..In ordnance training apparatus including an observation2instrument, the. combination, of a relatively. remote; target model, at.least one; stationary; rail, a carriage. mounted on said; rail, a rotorrotatable; onv said carriage. about a. vertical axis, a support. forsaidmodel onv said, rotor rotatable-about axis disnlaeedfrom the-aXis-Qfrotation of said rotor, meehanism formovingsaid carriage, and meansdriven independently of; said mechanism for rotating at least; saidsupport, whereby said model is; oriented in, the, field of View of; saidinstrument.v

3., In ordnance; training, apparatus, including an observation:instrument, the. combination, of a relatively remote target. model, at,leastone stationary rail, a carriage, mounted onsaid: rail, a rotor.rotatable on said carriage about. avertioal axis, a. support for saidvmodel on said rotor rotatable about an axis; d-isplacedfrom the axis. ofrotation of said rotor, mechanismfor. moving said carriage, means drivenindependently of said mechanism for rotating; said rotor-, and meansresponsive to. rotation of said. rotor for rotating said support in theopposite: direction, whereby apparent course of: said model ismaintainedduring;its; travel in the field of view of said: instrument.

4.. In ordnance training. apparatus including an observation instrument,the combination, of a nl urality of relatively remote target. models, abodily movable-rotor, aplurality of rotatablesug ports for said targetvmodels; mounted on... said rotor at points displaced from the axis;thereof; means for bodilymovingsaid rotor means; driven independently ofsaid last named means 01 ro s tating the; rotor about a. substantiallyvertical axis, and, means responsive; to rotation. oi the rotor, forsimultaneously orienting said, target modelsupports on said rotor.

5. In ordnance training apparatus including an observation instrument,the combination. of a. plurality of relatively remote, target models, abodily movable rotor, a plurality of rotatable supports, for said targetmodels; on: said, rotor, mechanism connected to said rotor for; drivingthe same bodily to simulate. movement. oi the target models in thefield: of view of; said inst-111i.- ment, and means driven independentlyof, said mechanism for simultaneouslyrotating said model. supports on.said rotor aboutv substantially vertical axes to maintain the apparent.oourse of said models.

- 6. In ordnance training apparatus including an observation instrument,the combination of a plurality of relatively remote target: models, at

8; leastona stationary a ls a; car iage moun ed.- on aid red. a ro ormount d about; rtica a is n. aid; eanr as i, e ativ ly driv n: cabl a.DQ116554 riv n; by a d cable. perative. nn t on etween; aid. n lleuand;said. o nd mesh; anis riorm v s; aidarri se, o a able s n:n0rtafoe-saidmode1s on said. m on an me ns. e nons ve o o atio at saidrotor, o mulltan ou a rotating; said. od lsupports he. pposi e irectionwhereby sai mod l ng r: est-la mavehe me. cours n h fi l t view-,of s ae,dns.tnuinent. 7;. In! ordnance twining; appara us: l ding; an; oservation-a instrumen he; om ination. oi a; relatively: remote, Q31?!"so, a. rotor mounted; for} movement about aaliel' iifialzaXjfi on.saidcarriage, alu ural tx of. spacedtare .modo s ispo ed n a substantate: hor zon alnlan n sa d rotor: n the-field of: view- 0saidinstrument, mechanism orrmov nssa-idl iasame ns r en idss nd 81 h!-ofi said m shanism; o rota ing said r tor n. aid, ar iage o. si u ate mv me of said r et mo elszini hefie d o View of said ins ill.- ment. andmeans: resnonsiveto said moveme t for simu tansous s or en ing. s odelon.- sai rotor;- connt sa d o a on th reo to: main:- tain thea ogarentooursaoi said target; models; 8.. In: Qtdnano tra ning apparatus,ncluding n; observa ion n trume t. the omb na n Qt a. r atively: emot ar a e, a s ppo t. mo nt d fo Increment a out: a. verticala is on a d;- re a a l yoi: llacedi arge mo s s isoosed n; a; subs ant ally horizon alp a e o ai sun:

in the fie do v e oisaidns rumen m shm for mo i s. sai ca r age. m sriven nd pendentls of. said. me han m, r o ating si g o. simulate, moesa d; suppor n sa d. so. merit: said; tar e mode s n he; e d. i? i wof: said nstru nt. me .s; po s v to a d movement f r: simul aneous rieng aidm r els he eonoountes to sa d; r tat on to mai ain he. app rent; or e of t rge m0 o s.,. nd me ns: interpos d n ai as amed. m a sorsharksns ri n a ion f a d mode s a wi l 9-.. in. Qrduanoe ra ins; appratu i uding an observation instrument, the, combination oi a relativelyr mote; earriaga a. sun ort moun d or movemen about: a ver i al: axis.von. saidoallnose, morali yt sp ced. a -se ode s. dis: posed insubstantialla horizontal plane. sa d support: he fiel of; v ew of sa dnst umen mechanism for.- niorti a a d a r a moan riv n. dene dentz uofsa d meeh t i n 1 teting: aid s osoe n; aid. r ag to simul t mo ement.of said target. mo e s n; he; fi ld of view oi saidv ins rum nt, and: mans for G anains; the. position; of; t lea t. n o i m l relatively tothe positions oi; the, other models without changing, the a aren-tcourseor speed o any f he mode s...

10.. In: targe t askin r nin ap atus eluding. an obs rvati n; in r m nhe m inetion o a l a i ly remote carria e a ro o mounted for rotationabout a substantially vertical; axis on said: carriag; 3 mechanism formoving said oarriage, means driven independently-oi said mech nis to roating; s i o or, a p ur it o sh nes-oasis mounted-in n r d posi i n. n.t nderside oi said ro or a ut: said s. nd at l ast one xibl Q ainsuspenddi' m sa d rot-0.1: ehind sai mo e s or s vey ng m vement relatie y t ere in s mulati n; of, e sur s-cast th se ii... In a rget.- trackns rain g appa atus, the. domination of a, carriage, e m q for rotationthereon about a vertical axis, a plurality of ship models simulating aconvoy disposed on said rotor between the periphery and the centerthereof, center gearing for orienting corresponding models through thesame angle, a plurality of separate gears mounting outlying modelsadjacent the periphery of said rotor, shafts extending from said centergearing to said separate gears for orienting said outlying models onsaid rotor, mechanism for rotating said rotor on said carriage aboutsaid vertical axis, and connections between said mechanism and saidcenter gearing for causing like orientation of all of said models uponrotation ofsaid rotor to simulate maintenance of course of said convoy.

12. In a target tracking training apparatus, the combination of acarriage, a rotor mounted for rotation thereon about a vertical axis, aplurality of ship models simulating a convoy disposed on said rotorbetween the periphery and the center thereof, center gearing fororienting corresponding models through the same angle, a plurality ofseparate gears mounting outlying models adjacent the periphery of saidrotor, shafts extending from said center gearing to said separate gearsfor orienting said outlying models on said rotor, mechanism for rotatingsaid rotor on said support about said vertical axis, connections betweensaid mechanism and said center gearing for causing like orientation ofall of said models upon rotation of said rotor to simulate maintenanceof course of said convoy, and means for changing the position of atleast one of said models relatively to the remainder without change ofspeed or course.

13. In a target tracking training apparatus, the combination of acarriage, a rotor suspended therefrom for rotation about a verticalaxis, a relatively rotatable shaft coaxial therewith, a radiallyextending element on said shaft having a rotary fastening memberdisplaced from the bers and the corresponding models through a commonangle to maintain the apparent course of the models, and meansindependent of said last-named means for rotating said shaft and thesaid element for changing the relative position of the correspondingmodel relatively to the other models.

14.'In a target tracking training apparatus, the combination of acarriage, a rotor suspended therefrom for rotation about a verticalaxis, a relatively rotatable shaft coaxial therewith, aradia'lly'extending element on said shaft having a rotary fasteningmember displaced from the axis of said shaft, gearing interposed betweensaid" shaft and said rotary fastening member for maintaining theorientation of the latter, a plurality of additional rotary fasteningmembers disposed in said rotor between said shaft and the peripherythereof, a plurality of inverted target models movably connected tocorrespond- 'ing rotary fastening members, means responsive axis of saidshaft, a plurality of additional rotary to rotation of said rotor forsimultaneously orienting said additional rotary members and thecorresponding models through a common angle to maintain the apparentcourse of the models, and means independent of said last-named means forrotating said shaft and the said element for changing the relativeposition of the corresponding model relatively to the other mod elswithout changing the orientation of said corresponding model.

EUGENE ODIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,317,556 Cooper Sept. 30, 19192,042,697 Baranoif June 2, 1936 2,364,070 Haile Dec. 5, 1944 2,381,757Jones Aug. '7, 1945 2,387,153 Johnson Oct. 16, 1945 FOREIGN PATENTSNumber Country Date 602,622 Germany Aug. 15, 1936

